Apparatus and method for transfer and slurrying or dissolving hydratable dry bulk chemicals

Abstract

An apparatus for the transfer of a dry chemical is formed having a sealed solvation hopper positioned between a liquid driven eductor and a fitting for connection to a storage container, e.g. a railcar. At the inlet end of the solvation hopper is a chemical inlet pipe which connects the interior to the exterior of the hopper. Surrounding the chemical inlet pipe are a plurality of nozzles for the introduction of solvation liquid into the hopper. The nozzles are disposed such that the solvation liquid washes the interior surface of the hopper to prevent plugging by hydrates (solvates) which may be formed. At the outlet end of the hopper, the hopper is connected to the suction opening of a liquid eductor. In use, the exterior end of the chemical inlet pipe is connected to the dry chemical storage container. Liquid flowing through the liquid eductor creates a suction and draws dry chemical out of the storage container and into the hopper. In the hopper, solvation liquid is supplied through the nozzles to wet the dry chemical and to wash the surfaces of the hopper, pushing the wetted material toward the outlet end of the hopper. At the outlet end of the hopper, the wetted material is sucked out into the eductor where it is combined with the flow of eductor liquid. The material leaving the eductor is recovered and sent either to storage or directly for processing.

We claim: 
     
       1. A method for transporting a dry chemical out of a container and introducing the dry chemical into a liquid carrier medium comprising: (a) connecting to the container an apparatus comprising a solvation hopper formed from a wall member, and an inlet end member and having an outlet end opposite to the inlet end; a plurality of spray nozzles disposed in the inlet end member of the hopper; means for supplying a flow of solvation liquid to the spray nozzles; a chemical inlet pipe passing through the inlet end member so as to connect the interior and the exterior of the hopper; and a liquid driven eductor having a liquid inlet pipe, a liquid outlet pipe and a suction opening, said suction opening being attached to the outlet end of the hopper, wherein the hopper is a sealed unit such that liquid flow through the eductor generates a suction within the chemical inlet pipe, and wherein the spray nozzles are oriented such that solvation liquid flowing through the spray nozzles washes the interior surface of the all member;   (b) supplying a flow of eductor liquid to the liquid driven eductor so as to such the dry chemical from the container into the hopper;   (c) supplying a flow of solvation liquid to the spray nozzles such that the dry chemical in the hopper is mixed with the solvation liquid to form wetted chemical which is sucked out of the hopper through the suction opening of the eductor; and   (d) recovering the chemical in a liquid carrier medium from the eductor outlet pipe said carrier medium comprising a combination of the solvation liquid and the eductor liquid, wherein the solvation liquid is supplied in an amount of 0.1 to 4 times the quantity "Z", where "Z" is the solvation flow rate expressed as gal/lb of solid and ##EQU2##   
     
     
       2. The method according to claim 1, wherein the solvation liquid is supplied at a flow rate sufficient to prevent plugging of the hopper by the wetted chemical. 
     
     
       3. The method according to claim 2, wherein the dry chemical is soda ash or calcium chloride, and the solvation liquid comprises water. 
     
     
       4. The method according to claim 1, wherein the container is a railcar. 
     
     
       5. The method according to claim 4, wherein the solvation liquid is supplied in an amount of 0.5 to 2 times "Z", where ##EQU3## 
     
     
       6. A method according to claim 4, wherein the solvation liquid and/or eductor liquid comprises a saturated solution of the dry chemical being transported in a solvent. 
     
     
       7. The method according to claim 1, wherein the solvation hopper has a volume such that the nominal residence time of the solvation liquid in the solvation hopper is 0.5 to 30 seconds. 
     
     
       8. The method according to claim 1, wherein the solvation hopper has a volume such that the nominal residence time of the solvation liquid in the solvation hopper is 0.5 to 10 seconds.